Some optical devices, such as, for example, rear projection television systems and digital micro-mirror (DMD) based image presentation devices employ multiple light sources having different colors. In order to support full color display capability, it is from time-to-time necessary for such devices, to combine the light output from the various color light sources into a common light path. While LEDs have, for some time, been used in various light source applications, such applications have generally been limited to low power and small screen image presentation devices. Due to advantages like lower cost, longer life, lower power consumption, and broader color gamut, when compared to conventional short-arc lamp light sources, there exists a growing need for semi-conductor based illumination modules and light engines capable of high power and very high collection and throughput efficiencies. To this end, there is a need to provide illumination and light engine solutions that offer advantages in compactness, simplicity, low cost, and speed of operation.
The above and other features and advantages of the invention will be further understood from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings.